Measurement of multiplicity and momentum spectra in the current fragmentation region of the Breit frame at HERA

TL;DR

This paper investigates how charged particle multiplicity and momentum spectra evolve with energy scale in deep inelastic scattering at HERA, testing QCD coherence and quark fragmentation universality by comparing with electron-positron data.

Contribution

It provides detailed measurements of charged particle spectra in DIS and compares them with e+e- data to explore QCD coherence and fragmentation universality.

Findings

Charged multiplicity increases with Q^2.

Momentum spectra show scaling behavior.

Results support universality of quark fragmentation.

Abstract

Charged particle production has been measured in Deep Inelastic Scattering (DIS) events using the ZEUS detector over a large range of $Q^2$ from 10 to $1280 {\rm\ GeV}^2$. The evolution with $Q$ of the charged multiplicity and scaled momentum has been investigated in the current fragmentation region of the Breit frame. The data are used to study QCD \linebreak coherence effects in DIS and are compared with corresponding \ee~data in order to test the universality of quark fragmentation.